5205 will not start

[marcin]

Hi all,

The 5205 has been a great tractor thus far. All of a sudden, it will not start - I have not had this problem before. The tractor cranks well. There is fuel in the tank and in the final filter but it will not start. Is this a possible electric problem or a bad injection pump? I looked at part diagrams but could not find a booster pump on this tractor. Where do I start and what is the most likely cause of the problem? Thank you for your help.

Marcin

 

[beenthere]

Fuel filter ok? No water in bowl? Would be my first guesses.

 

[marcin]

The final fuel filter seems to be ok. It was full of diesel. I do not have a water bowl. The prime handle on the final filter will not stay down - I am not sure if it is supposed to unless the tractor is in operation. Would the next step be to unscrew the line to injection pump and see if fuel comes out? Where is the priming/ booster pump?

 

[JD5210]

Are you blowing any fuses? And does the fuse blow as soon as you turn the key?

If yes, to both questions, I believe the problem is the thermistor sensor (thermistors are temperature variable resistors used as sensors.). On the thermostat housing there is a sensor that is connected to a two wire harness that goes to the injection pump; this is the "cold start advance" portion of the system so it starts easier when cold by advancing the timing.

When the sensor on the thermostat housing fails it shorts out and blows the fuse. Try unplugging it, replace fuse and see if it starts and runs. The part # is RE503242, if you are quick changing it, you don't have to drain the coolant, just make sure it's not hot at the time. You will want a pan under the tractor to catch the coolant, so as not too have to clean it up.

To comply with the exhaust emissions regulation, the timing of injection pump should be around 6 to 9 degrees before TDC. These timing values do not allow proper start-up operations when engine is cold. To ease engine start-up, a cold advance system gives to the injection pump a temporary over-timing.

When coolant temperature is below 50 C (122 F), the solenoid valve is activated and opens the cold advance circuit.

 

[marcin]

Yes, a fuse in location 2 behind the ignition switch panel was blown. I changed it and tried starting - it blew immediately. I am not sure if this is the fuel shut off solenoid or not - or is that fuse in a different location? I will try disconnecting the harness tomorrow and seeing. Thank you for the valuable info.

 

[MF283]

As JD5210 stated, unhook thermistor & change fuse, it should start if that's the cause.

Ronnie

 

[Tx Jim]

It's difficult for me to understand why JD engineers haven't discovered the solution for this part failure that's been failing consistently for nearly 20 years.

 

[MF283]

It's difficult for me to understand why JD engineers haven't discovered the solution for this part failure that's been failing consistently for nearly 20 years.

At $40+ a piece, i can figure it out Tx Jim, can you think of any harm it could cause not leaving it hooked up?

Ronnie

 

[Tx Jim]

Only thing I think is required of sensor is to appease the EPA. I still can't understand how the sensor changes IP timing when temp is low. Basically same diesel engine started and operated fine for yrs without the sensor.

 

[MF283]

Only thing I think is required of sensor is to appease the EPA. I still can't understand how the sensor changes IP timing when temp is low. Basically same diesel engine started and operated fine for yrs without the sensor.

My thought's exactly.

Ronnie